#1 limestone, also known as #1 stone, large crushed limestone, coarse limestone aggregate, or stabilization stone, is an oversized, angular aggregate used for heavy-duty construction, drainage, and ground stabilization. It commonly contains stone ranging from approximately 2 inches up to 4 inches, although exact gradation and maximum size may vary by quarry and regional specification.
The large particle size creates substantial open space between the stones, allowing high volumes of water to pass through without the material becoming easily clogged by sediment. Its rough, fractured edges help the limestone interlock and distribute heavy loads more effectively than rounded gravel, making it well suited for soft ground, wet areas, and demanding construction environments.
#1 limestone is commonly selected when smaller aggregate would sink, shift, or fail to provide enough stabilization. It can be placed as the first structural layer over weak subgrade, mud, or unstable soil before smaller base stone is added above it. Because the material has large voids and does not create a smooth finished surface, it is generally used as a deep base, drainage layer, or construction fill rather than as a driveway topping or walking surface.
Common Applications of #1 Limestone
- Road base reinforcement and deep sub-base stabilization
- Construction entrances and heavy-equipment access areas
- Stabilizing soft, muddy, or unstable ground
- Large drainage trenches and stormwater systems
- Culvert bedding and drainage outlet protection
- Foundation and retaining wall backfill
- Structural fill beneath roads and parking areas
- Base layer beneath smaller crushed aggregate










